A 200 m long rain is running at a speed of 54 km/hr. On the parallel and a different track, another train 300 m long is running at a speed of 72 km/hr. Both the trains are running in the same direction. Find out how much will it take the train to cross each other?

We know that, when the trains are moving in the same direction,
Relative speed= Difference between the speed of train
and total distance for crossing each other = Sum of the length of train
Therefore, Relative speed = 72 km/hr - 54 km /hr = 18 km/hr
Relative speed in m/sec = 18 km/hr x 5/18 = 5 m/sec
and Total distance = 200m + 300m = 500m
and Total time taken to cross each other = Total distance in meter/ Relative speed in m/sec
= 500 m / (5 m/sec) = 100 sec